On July 8, Dr Bob Brown, former leader of the Greens and defender of the Franklin River, spoke out against a proposed wind farm on Robbins Island on the north coast of Tasmania. I say “on”, rather than “off” because it can be walked to at low tide, and the landowners’ Wagyu beef cattle do just that.
Foremost among Dr Brown’s concerns was the potential impact of 163 wind turbines on birds, especially the endangered Tasmanian wedge-tailed eagle (Aquila audax fleayi) and the white-bellied sea-eagle (Haliaeetus leucogaster).
Dr Brown drew heavy criticism—not for speaking out about the potential impact of the wind turbines on the birds, but mostly for not speaking out earlier when other wind farms were constructed in Tasmania and on the Australian mainland. Dr Brown was accused of hypocrisy, having very prominently led the opposition to the Adani coal mine in Queensland during the election campaign in May, where the mere presence of the “endangered” black-throated finch (Poephila cinctaI)—listed on the International Union for Conservation of Nature’s “Red List” of endangered species as of “least concern” and not even “endangered”—was used to delay approval for the mine. The Tasmanian wedge-tailed eagle is endangered, but while there has been concern from bird lovers there has not been even an invocation of the precautionary principle from the environmental movement, as wind farms have been built at Woolnorth (north-west corner of Tasmania) and Musselroe (north-east corner) and approved at Cattle Hill (central plateau).
“Where we have strong emotions, we’re liable to fool ourselves.”
It is widely known that wind turbines and birds do not mix, and the impact of turbines on raptor species is particularly concerning. This is because of the population dynamics of species such as wedge-tailed eagles, which take four to six years to reach breeding maturity and form breeding pairs, and usually produce only one live chick a year.
Wedge-tailed eagles (Aquila audax) are widespread on mainland Australia, but the Tasmanian distinct subspecies (fleayi) is endangered, with only an estimated 350 breeding pairs remaining, having been hunted in the past with a bounty (like the extinct thylacine). It is listed as endangered because it has a population of less than 1000 mature individuals, which may be declining due to a number of identified threatening processes. These include loss of habitat, especially nesting habitat, nest disturbance, unnatural mortality persecution (shooting, poisoning, trapping), collision (powerlines, vehicles, fences, wind turbines) and electrocution.
Dr Brown’s concern for eagle deaths at Robbins Island was not shared universally, however. The national co-ordinator of the Australian Wind Alliance, Andrew Bray, was quoted in the Mercury as stating, “For every one bird killed by a wind turbine, nuclear and fossil fuel-powered plants kill 2000.” We will return to examine this claim later, as it is based on a clear example of noble-cause corruption in environmental science, which suggests that caution is needed when considering risk evaluations related to avian mortality and wind farms.
This essay appears in September’s Quadrant.
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Certainly, Dr Brown and environment groups had not objected particularly to the construction of the Woolnorth Wind Farm, built on two sites: Bluff Point (thirty-seven turbines, 65MW, opened in 2004); and Studland Bay (twenty-five turbines 75MW, opened in 2007). Neither had there been much concern over the (soon abandoned) proposal for a wind farm on King Island in 2012, despite the island being on the route of the annual migration of the orange-bellied parrot (Neophema chrysogaster) from the mainland to south-west Tasmania, with Tasmanian wedge-tailed eagles and white-bellied sea-eagles also present. Similar relative silence surrounded the construction of the Musselroe Wind Farm (fifty-six 3MW turbines, 168 MW, commissioned in 2013-14) or the more recent Cattle Hill and Granville Harbour proposals. Yet wind farms are killing eagles. On July 27, the Australian reported that Woolnorth Wind Farms Holdings’ two sites had recorded the recent deaths of two Tasmanian wedge-tailed eagles and one white-bellied sea-eagle. It had recorded the deaths of thirty-two wedge-tailed eagles and five sea-eagles across its wider operations since 2002 (Denholm, 2019). Craig Webb, who runs a raptor refuge in southern Tasmania, says the toll is known to be “much, much higher”.
Why, then, were there concerns for eagles at Robbins Island now when there were so few about Woolnorth or Musselroe? Part of the reason seemed to be both the number and size of the Robbins Island turbines: 163 turbines, up to 270 metres from ground to blade tip. But while Dr Brown also mentioned the aesthetics of such large turbines, his main concern was with the impact on eagles, and (if anything) larger turbines are safer than small (though perhaps not so for bats). The avian impact of wind turbines first achieved notoriety with the farm at Altamont Pass in California, where the small turbines used proved particularly dangerous to various raptors that hunted California ground squirrels, with some suggestions that they were attracted to their deaths by the prey seeking refuge under the spinning blades where they knew they were relatively safe. There were reportedly 1300 raptors killed annually, including seventy federally protected golden eagles in a total of 4700 birds killed annually. Since Altamont was built there has been a reported 80 per cent decline in golden eagles in Northern California, with none nesting near the facility, despite it being a prime habitat (see the video below).
The contrast between concern for the black-throated finch and the lack of concern for the Tasmanian wedge-tailed eagle can be explained by the fact that wind farms are considered to be a desirable response to climate change, and the nobility of the climate-change cause overrides concerns for endangered animals—which are otherwise useful as a reason for opposing disliked developments.
The eagle deaths at Woolnorth seem minor when compared with Altamont, but a more detailed examination suggests that Dr Brown is perhaps justified in being concerned, both because the numbers at Woolnorth are almost certainly an underestimation, and because the numbers there and those likely at further wind farms do give cause for concern, especially over cumulative impacts.
ABC news reported on September 21, 2007, that ten wedge-tailed eagles had been killed by turbines at Woolnorth since it commenced operation in 2003. Dr Cindy Hull has studied bird deaths at the Woolnorth wind farms while working for Sustainability and Safety, Hydro Tasmania, part-owner of the facility. In published research (Hull et all, 2013) she and her co-researchers reported that by 2009 (with Studland Bay operational only since 2007), 1228 carcass surveys at both sites revealed eighteen wedge-tailed eagles and three sea-eagles had been killed, among 245 total bird mortalities.
Professor Corey Bradshaw in his Assessment of the Tasmanian WTE Collision Risk Model (CRM) for the Cattle Hill project in 2011 suggested that the original CRM estimate for Woolnorth of 0.27 to 0.79 mortalities per annum was at least two to five times lower than the minimum observed number—likely even lower assuming missed carcasses. The annual rate of eagle mortality at both Woolnorth wind farms has now been acknowledged by the owner to be 3.2. This is a minimum estimate, however, “based on carcasses (or mortally injured birds) where the death/injury can definitely be attributed to a collision with a wind turbine” (Board of the Environment Protection, 2011: 15).
This underestimation of mortality in the approval process seems to be a continuing problem. Material presented for the approval of the Macarthur wind farm in Victoria estimated it would kill two birds per turbine a year, but monitoring since construction has shown the farm was killing 13.4 birds per turbine a year, more than six times the pre-construction estimate, and a similar underestimate to that for Woolnorth. The permit application also claimed a raptor annual mortality of three for the whole farm, but since construction there have been an estimated toll of 430 raptors a year, which is 30 per cent of total bird deaths (Lloyd, 2019; Wood, 2015).
There is, therefore, uncertainty over the mortality of eagles as a result of wind turbines. One of the leading eagle experts, wildlife biologist Nick Mooney, has stated that it is hard to estimate how many eagles are killed by wind turbines, stating “Most eagles found dead are found immediately under the turbines, but that’s only the ones killed instantly or catastrophically injured … We have no idea how many wobble off and die elsewhere.” (Howarth, 2018) In addition to eagles “wobbling off”, eagles and other species feed on carrion, and can carry them off, and so the counts of carcasses under turbines are always considered to be an underestimate. Techniques have been developed internationally to correct for these factors, but even adjusted figures are considered to be conservative, because when there are no carcasses found there are no data to adjust, so some kills are simply missed.
The uncertainty surrounding eagle mortality counts was highlighted by the monitoring of bird and bat mortalities at the Macarthur wind farm over twelve months in 2014-15. Searches revealed two wedge-tailed eagle carcasses, but another thirteen bird carcasses were found incidentally near turbines by maintenance personnel, landowners or ecologists when not undertaking scheduled carcass searches. These included seven wedge-tailed eagles (Wood, 2015: 11-12).
Documentation for the approval of the Cattle Hill Wind Farm presented modelling suggesting that, “worst case”, 2.1 wedge-tailed eagles would be killed annually at Cattle Hill, and that this would be below the number of mortalities the subspecies could sustain “before encountering a ‘tipping point’ which would increase the species risk of extinction” (Board of the Environment Protection, 2011:14). (Note the reference to “species”, whereas the Tasmanian eagle is merely a subspecies.) The “tipping point” figure was twenty-two deaths annually. There are serious questions, however, about the future population of the Tasmanian wedge-tailed eagle. Bekessy et al (2009) have modelled a likely decline over the next 160 years of about 65 per cent, most likely driven largely by loss of current and potential future nest sites associated with timber harvesting, exacerbated by unnatural mortality in the wider landscape.
Wind turbines are not the only cause of eagle mortality, of course. Collisions with vehicles, illegal shooting and so on also occur, and official data indicate that power lines kill about thirty wedge-tailed eagles each year, largely through collisions (Threatened Species Section, 2006). The additional transmission lines needed for wind farms add to this toll, and the impact varies according to distance to the existing transmission network—short for Cattle Hill, but substantial (170 kilometres) for Robbins Island. Because solar and wind sources are less dense by area than hydro or thermal electricity and have lower load factors, more transmission lines are required per GWh of energy.
There are currently ten new wind farms proposed or under construction in Tasmania, which would bring another 500 turbines. The uncertainty surrounding eagle mortalities raises concerns about the cumulative effect of these developments, when added to the current sources of mortality. These concerns are exacerbated by the fact that the data on mortalities at Woolnorth, the source of most existing data, have come from employees of the owners which, together with the enthusiasm for wind energy among environmentalists, can place what Iain Boale has termed a “value slope” across research, which can result in a greater likelihood that (even unconsciously) favourable assumptions will be made and an outcome more favourable to wind energy will result than might be the case if the research were undertaken by those with no preference for wind energy.
The attitude that a few birds (in this case orange-bellied parrots) should not impede the march of renewables as a response to climate change was exemplified by the testimony of Dr Christian Downie, now of the ANU, but then with the Australia Institute, to a New South Wales Parliamentary inquiry on September 11, 2009, who stated, “I think we have to make sure that we do not use two or three bird deaths—let us not go to exact numbers—but a small number of bird deaths to justify scrapping a big wind farm.” This kind of attitude is common in environmental science, where a strong moral sense can lead to questionable interpretive practices (QIPs) as moral purpose affects the psychology of the scientists, which impedes the availability of good evidence to inform policy—not necessarily by any conscious act. Established QIPs include: blind spots (overlooking data inconsistent with one’s moral agenda); selective preference (accepting research supporting one’s agenda, but subjecting opposing research of comparable or greater quality to criticism); and phantom facts (drawing implications without evidence) (Jussim et al. 2016).
This threat of what I have called “virtuous corruption” (known as noble-cause corruption in law enforcement circles) (Kellow, 2007) appears to be rife in studies surrounding renewables and bird mortality, which we can demonstrate by examining in detail the claim (noted above) that the impact that wind energy produces lower mortality than thermal electricity generation—both fossil fuel and nuclear.
Virtuous Corruption in Avian Mortality Studies
This claim, made frequently by wind power advocates, derives from research by Benjamin Sovacool. We should ignore the fact that Sovacool acknowledged support for his research from the wind industry, including the operators of the notorious Altamont Pass wind farm. To dismiss his research on these grounds would be to commit the genetic fallacy, so common among climate activists, who dismiss inconvenient research as they play a kind of “six degrees of separation from Exxon Mobil” game. The origin of research does not establish its veracity or otherwise. There are, however, many things wrong with Sovacool’s research.
First, Sovacool cites some examples of bird strikes at thermal stations, where birds have died after collisions with cooling towers and emission stacks. He then extrapolates these mortality rates, scaling up installed capacity and assumptions of capacity factors to all thermal generation in the United States. But his examples come from the 1990s and early 2000s, and Temme and Jackson in 1979 found this to be only a minor problem that could be mitigated with appropriate lighting of towers and stacks at night for nocturnal migrating birds.
To estimate wind power mortality, Sovacool used data from wind farms in Minnesota, Oregon, Washington, West Virginia and Wyoming—though not from California where the Altamont Pass wind farm owned by one of his sponsors and apparently responsible for alarming numbers of eagle mortalities is located. (Nor from Idaho, the location of his other sponsor.) So he omits the worst example for wind, but cherry-picks the worst examples for many sources of mortality for thermal electricity. Similarly, while including the total fuel cycle for nuclear and fossil fuels, he neglects entirely the several hundred tonnes of steel in every wind tower and cement and reinforcing steel in their foundations. These materials require the combustion of coal to manufacture, with about 550 tonnes of coal used to make a 2MW wind turbine. Sovacool does not account at all for these emissions—in stark contrast to his inclusion of the modelled future deaths of birds as a result of climate change.
This continues Sovacool’s comparing of the “apples” of actual carcasses with the “oranges” of virtual deaths, of modelled deaths, but also of documented past deaths with future possible deaths. But future possible deaths from climate change constitute fully 97.9 per cent of the 9.36 deaths per GWh that Sovacool attributes to fossil fuel generation. Even then, Sovacool’s analysis is tipped in favour of wind.
Willis et al (2010) pointed out that in his 2009 paper, Sovacool (in addition to conflating birds and bats as “avian species”) used mortality estimates that were not corrected for searcher efficiency and scavenger losses, despite the fact that corrected data were available. Using the corrected estimates, the estimated number of birds killed at the six wind sites in Sovacool’s study increased to 0.653/GWh, more than double his estimate of 0.269/GWh. Willis et al pointed out that there were twenty-one sites for which corrected data were available, and when these were included in the analysis, the average number of birds killed rose to 1.46/GWh, or more than five times Sovacool’s original estimate.
In his 2009 paper Sovacool also failed to include mortality due to transmission lines for wind power but included it for fossil fuels. Not only do wind farms require transmission lines, they actually require proportionately more because of their low energy density and low load factors. Sovacool also estimated habitat loss resulting from fossil fuel extraction as a source of mortality, but ignored habitat loss associated with wind turbines, which require the clearing of vegetation. Willis et al pointed these faults out in 2010, but the errors persisted in Sovacool’s 2012 paper. Even his analysis of habitat loss for coal extraction was based on highly selective data, focusing on mountaintop removal and valley-fill operations in four states—Kentucky, Tennessee, Virginia and West Virginia. This impactful coal mining technique was scaled up as if it could be regarded as typical of coal mining for the whole US, but it cannot. Techniques used in Appalachia are not typical of the whole US, and neither are the states selected the most significant. Collectively, the four states produce less than 20 per cent of US coal, with Tennessee producing a scant 0.8 million short tons in 2014. Sovacool, on coal at least, is oblivious to Wyoming, which alone accounts for about 42 per cent of US coal production.
When he turns to the impact of the nuclear fuel cycle, Sovocool is aware of Wyoming, because a single uranium mine in Wyoming produces about half of US domestic yellowcake. The largest contribution to Sovacool’s nuclear power impacts comes from uranium mining and milling operations. Most of the mines in Wyoming closed with the drop in prices in the 1980s, so to extrapolate from the single mine there is inappropriate anyway, but in his 2009 paper he focuses on two uranium mining operations he locates in Wyoming where he claims that bird deaths are caused by abandoned open pits.
The first mine is the Canon City Uranium Mine, actually in Colorado (rather than Wyoming), which has operated only intermittently since 1979. The owners of the mine were fined when a one-off kerosene spill killed forty geese in 2008 (Lorenzini, 2013). The operators were required to prevent further spills, but Sovacool assumed the death of forty geese was a routine occurrence, and scaled it up for all nuclear electricity generation. His second example was even more egregious, and did not even involve a uranium mine, but an abandoned copper mine in Montana. His 2009 paper refers to the hazards of open-pit uranium mines in Wyoming where, he states, it is not uncommon for these pits to kill 300 birds per year. His authority is a US Fish and Wildlife report where the only bird death claim refers to the death of 300 snow geese in 1995 at the infamous Berkeley Pit mine in Montana, one of the country’s largest superfund sites, which was a copper mine operated by Anaconda Copper Company from 1955 to 1982.
A single incident in an abandoned copper mine in Montana is assumed to be an annual occurrence at uranium mines and used as the basis for estimating a mortality rate for all US reactors. Sovacool’s 2012 report excludes (without explanation) the lower mortality rate from Canon City and takes the higher figure from the Berkeley Mine to be the bird-kill impact for all uranium mining operations. But it gets worse, because total US production represents only about 7 per cent of the anticipated uranium market requirements of US nuclear power reactors. The balance is imported.
These mortality rates pale into insignificance, however, compared with that which Sovacool presents for future climate change from fossil fuels: 9.16 deaths per GWh from power stations fuelled by oil, natural gas and coal, for a total of 9.36 fatalities per GWh. He bases this on a single paper published in 2004.
Using the species-area model derived from island biogeography (relating number of species to area) to predict species distribution in response to modelled climate change (in turn based upon emissions scenarios), this paper (Thomas et al, 2004) concluded its abstract with a call to action: “These estimates show the importance of rapid implementation of technologies to decrease greenhouse gas emissions and strategies for carbon sequestration.” No evidence was presented in the paper to support this proposition, which was taken to be a self-evident truth, yet the paper’s prediction that a million species might eventually become extinct as a result of climate change over the next fifty years was based on an analysis of only 1103 species, an extrapolation that was then further exaggerated by both the media and political actors. But the nobility of the cause was thought by some to outweigh any concern over accuracy and exaggerated use, with one communication in Nature being titled “Extinction-risk Coverage is Worth Inaccuracies” (Hannah and Phillips, 2004), and another scholar stating that “the major usefulness of such exercises is in destroying any residual complacency about climate change among conservationists and hopefully among policy makers”. (Lewis, 2006: 170). As I once put it when discussing this paper: “That is to say, it is acceptable to bullshit as long as it is done in a good cause.” (Kellow, 2007: 150).
Sovacool’s work is a perfect example of the “virtuous corruption” to which much environmental science is vulnerable, thanks to its reliance upon modelling. The antidote against such corruption, which tends to produce “policy-based evidence”, is an insistence on adherence to essentially Popperian tests of veracity, such as that laid down by the US Supreme Court in the Daubert case, insisting on open disclosure of data and methods, of criticism and repeated attempts at falsification, and so on.
The heated nature of climate politics, with sceptical voices being likened to Holocaust deniers, tends to inhibit the scientific liberalism required, and the nobility of the cause of “saving the planet” has also inhibited the preparedness of environmental activists—until Bob Brown’s recent Damascene conversion—to voice concerns about the environmental consequences of wind and solar energy.
The silence from environmental activists over the impact on Tasmanian wedge-tailed eagles of the Woolnorth and Musselroe wind farms is, unfortunately, typical globally. Michael Shellenberger has noted that Friends of the Earth, Greenpeace, the Natural Resources Defense Council, the Environmental Defense Fund and the Sierra Club, which have for forty years “hyped fears that the slightly warm, clean water that exits nuclear plants might harm local aquatic life” are now actively justifying deaths at wind and solar plants by “hyping future potential bird deaths from climate change” and making a “deceitful house cat comparison”.
Sovacool, predictably, also cites the number birds killed by domestic (and feral) cats, but this ignores that fact that most cats kill birds that are aged or infirm, and—unlike wind farms—tend not to kill eagles. In fact, cats are more likely to be carried away by eagles—much as Sovacool and environmentalists have been carried away by the attractions of wind energy.
All energy utilisation has an environmental impact. It also has an economic impact, and policy-makers are only beginning to wake up to the fact that renewables can mean higher prices without reducing greenhouse gas emissions, as Germany has found recently. In addition to familiarising themselves with issues such as “The renewable energy policy paradox” (Blazquez, et al., 2018), policy-makers need to apply critical scrutiny to the impact of wind energy on the environment, including endangered birds such as the Tasmanian wedge-tailed eagle.
Despite the best efforts of those who count the dead birds, we really have little idea of the actual numbers of eagles killed at Woolnorth and elsewhere, and what the cumulative effect of additional wind farms in Tasmania will be. Albeit belated, Bob Brown’s concerns are to be welcomed.
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